This invention is particularly directed to a manufacturing process for making minute, substantially homogeneous globules, generally termed herein as microglobules, which include a matrix material of hydrophilic, film-forming, polymeric material (such as gelatin), having dispersed therein oil-insoluble payload material, which payload material may be either water soluble or water-insoluble but is at least water-wettable and water-dispersible.
The art has long taught methods of making substantially non-homogeneous microparticles, namely, microcapsules having discrete zones of solid exterior wall-material and internal payload material, the latter generally being liquid. the microcapsules of the art have largely been made by coacervation, that is liquid-liquid phase separation, and have generally been limited to microcapsules having hydrophobic wall material containing hydrophilic payload material on the one hand or microcapsules having hydrophilic wall material containing hydrophobic payload material on the other. Representative of the art are the following patents: U.S. Pat. No. 2,800,458 (Green) and U.S. Pat. No. 2,800,457 (Green & Schleicher), which teach the manufacture of microcapsules by coacervation wherein the microcapsules have hydrophilic wall material and oily internal-phase payload material, made by coacervation of hydrophilic, polymeric, film-forming material in an aqueous external vehicle, to wrap and encapsulate oil-droplets dispersed in the aqueous vehicle; U.S. Pat. No. 3,589,910 (Nesmeyanov et al.) which teaches the incorporation of generally oil-insoluble payload material droplets in hydrophilic wall-material by coacervation within an aqueous droplet, which aqueous droplet originally contains both the wall material and the payload material and which droplet is dispersed in an oil vehicle; and British Pat. No. 931,148 (Wagner) which teaches the manufacture of microcapsules by coacervation wherein the microcapsules have hydrophobic wall material and aqueous internal-phase payload material, made by coacervation of hydrophobic polymeric film-forming material in an oily external vehicle to wrap and encapsulate aqueous droplets dispersed in the oil vehicle.